1. Field of the Invention
The present invention relates to a suction device for a powered vacuum apparatus.
2. Description of the Related Art
A hand-held, powered vacuum apparatus which draws in garden debris such as leaves and a dust by using a suction pressure of a centrifugal blower to collect the debris into a bag or the like that is attached to a blowing tip is known. FIG. 1 shows an example of a conventional hand-held powered vacuum apparatus (refer to Japanese Laid-Open No. 2000-179497; FIG. 1A is an external view and FIG. 1B is a front view of a fan case).
In this conventional example, a main body 1 is integrally formed by a motor 11 for driving a fan 10, a recoil starter 12 for starting, a fuel tank 13, and a fan case 14 or the like. A suction pipe 2 is detachably coupled with an air intake opening 14A of a fan case 14 and a blowing pipe 3 is detachably coupled with an air blowing opening 14B of the fan case 14. A dust bag 4 having suitable ventilation property is attached to a blowing end of the blowing pipe 3. The example shown in the drawing is a hand-held apparatus and handles 15 and 16 gripped by an operator are mounted on the main body 1. In addition, in the air intake opening 14A of the fan case 14, a cutter 5 is provided, which is placed on a driving axis of the fan 10 to be rotated with the fan 10.
According to such hand-held powered vacuum apparatus, the fan 10 is driven due to start of the motor 11, and a garden debris such as fallen leaves, wood chips, and dust is drawn into the air intake opening 14A of the fan case 14 via the suction pipe 2 due to a suction pressure caused by blowing from the fan 10. Therefore, the debris is crushed by the cutter 5 to be rotated with the fan 10 and the crushed debris is transferred to the air blowing opening 14B passing through an air intake passage in the fan case 14 to be collected in the dust bag 4 via the blowing pipe 3.
In order to obtain a desired suction property, it is necessary for such a suction device for powered vacuum apparatus to provide a gap formed between a wing top part of the fan 10 and the inner wall of the fan case 14. If this gap is made too narrow, a drive load of the fan is made larger, and if this gap is made too wide, a suction force cannot be effectively generated.
Therefore, setting the above-described gap in order to obtain a desired suction property, a bar-shaped wood chip such as a branch and a plate-shaped wood chip or the like crushed by the cutter 5 into a thickness that they are easily sandwiched in the gap or a wood chip or the like originally having a thickness to be easily sandwiched in the gap, which slip through the cutter 5, may enter from the periphery of the air intake opening 14A into the inside of the fan case 14. Then, this involves a problem such that the wood chips which slip through the cutter 5 are sandwiched in the gap between the inner wall of the fan case 14 and the fan 10.
Thus, if the debris is sandwiched in the gap between the inner wall of the fan case 14 and the fan 10, the fan is locked according to the circumstance and this makes it impossible to continue the suction work. In addition, in the case that a relatively-narrow debris is sandwiched, the rotation of the fan 10 is continued with a foreign object sandwiched in the gap, so that the rotation of the fan 10 is prevented by friction and a desired suction property cannot be obtained. In the case of carrying out the operation in such a condition for a long period of time, it may be considered that the blade of the fan 10 and the inner wall of the fan case 14 are damaged.
Even if the front end of the cutter is elongated so as to be closer to the inner wall of the fan case 14, there is no effect on the wood chip or the like slipping through the cutter 5 since the crushing is not enough. Therefore, for this problem, a suggestion as described in the following Japanese Patent Application Publication No. 3-58604 is made, for example. According to this document, setting a fixed cutter blade on a part of the air intake opening 14A for the rotational cutter blade as the above-described cutter 5, the debris that is easily sandwiched between the inner wall of the fan case 14 and the fan 10 is further cut depending on a cooperation between the rotational cutter blade and the fixed cutter blade.